BL In telling a past-tense story, particularly one as vivid as this — if you haven't got masses of archives, like Capturing the Friedmans (2003) or Man on Wire (2008), you're limited in what you can do with photographs or animation. Here, you're experiencing a number of quite accomplished storytellers telling you this very extraordinary story, and I think that inevitably produces quite a visual experience. I wanted to recreate that movie that plays in your head when someone tells you a very compelling but very subjective story.

SFBG With a title like The Imposter, the audience knows the truth about Bourdin from the start — but the film is also able to suggest how his victims might have been fooled.

DD Over the course of the film, you spend a reasonable amount of time with this person who is lots of different things. He's engaging. He pulls you in. He makes you complicit in this thing that he's trying to achieve. And you kind of almost root for him, even though he's trying to do something which seems not only wrong but impossible.

As the film goes on, you understand that he's also a victim in some ways. He comes from this damaged place, and he's looking for love and looking for a family. But he also does things which are inexcusable, and at points, I think, looks like a psychopath. When we were talking about making the film, someone asked whether it was the right thing to do, to give this guy a stage from which to hold forth. Here he is, a con man, a convicted felon, and he's done terrible things to various people.

In a way it felt like allowing him that time wasn't about being fair to him. It was actually about being fair to the family, or everyone who's been conned. Because until you actually realize how charming and persuasive he can be, then you have no context for judging all of these people who were taken in by it, whether it's family members, the FBI, or the American government.

BL Interacting with him is quite complex. It's not just, "You're creepy and weird," it's "You're creepy, but now you're kind of sympathetic. I feel like I need to look after you a little bit. Now I'm falling for your story and beginning to understand your logic." Those are things we felt the audience needed to have some experience of directly.

DD The audience gets to go on this crazy journey — which is not dissimilar to the journey that we went on as filmmakers — and also follow the journeys that all of these individuals go on as their lives are impacted by these events. I hope the film presents a series of surprises that almost defy credibility — and are only redeemed by the fact that they're true.